


Carnage

by Amariys



Category: Assassination Classroom
Genre: Knifeplay, M/M, Set in 7YL Universe, future!Au, slight blood
Language: English
Status: Completed
Published: 2015-06-06
Updated: 2015-06-06
Packaged: 2018-04-03 04:06:34
Rating: Explicit
Warnings: Graphic Depictions Of Violence
Chapters: 1
Words: 4,799
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/4086013
Author URL: https://archiveofourown.org/users/Amariys/pseuds/Amariys
Summary: <blockquote class="userstuff">
              <p>Nagisa had mixed feelings about the nick his friends gave for him and Karma. KaruNagi pairing. Set in 7YL universe. Mature. Slight knife-play. Complete.</p>
            </blockquote>





	Carnage

**Author's Note:**

> This is the first assassination classroom fic I've ever written. My OTP is carnage pairing, so of course I just had to write about them. I blame the fabulous [popsky](http://archiveofourown.org/users/popsky/pseuds/popsky) for the whole idea. Also Nagisa plus knife equals incredibly sexy image and since I have this headcanon Karma loved that image so much, the knife-play kink was born. Oops?
> 
> Also cross-posted on my ffnet account.

Since the beginning—all those years ago when he first met with a certain complexity that was Shiota Nagisa—Karma had known the pretty-looking male was dangerous. Though Nagisa didn't give out the vibe that would make people unconsciously giving him wide berth (rather the opposite actually), Karma wasn't fooled. He had always believed there was something else beneath the fragile persona Nagisa had donned—and that was the reason he had been gravitated towards the other.

Karma was a curious person by nature. His intelligence allowed him to understand things faster and better than anyone else—and made the world such a boring place. Thus, he had always loved mysteries, especially those that seemed almost impossible to be solved, and Nagisa was the most interesting mystery he had ever encountered.

He wanted to know the bluenette better; to dig through that smiling mask he had worn; to pull out the darkest side of him and to bask in the newfound knowledge—the sheer power of it. The wish was so intense that sometimes Karma needed to restrain himself from physically clawing at Nagisa's (pretty,  _pretty_ ) face.

Patience had always been his virtue though—that and his sharp wits—and it proved to be worthwhile when Nagisa slowly started to open up to him. Karma counted it a victory when the bluenette didn't even bat an eye when he had asked where he would continue his study—and they ended up having the same class all through their high school years.

(Looking back, though, Karma now realized Nagisa had seen right through him. He must've noticed Karma's hidden plan and decided to play along with it.)

(Now that he had spent years together with him, Karma could actually—begrudgingly—admit Nagisa had always outwitted him.)

It was fascinating, to see the incredibly tight control Nagisa had over his feelings and bloodlust—and that control had gotten impossibly  _better_  since they had to spend their time in a normal, boring high school which had nothing to do with assassination at all—that Karma had never gotten tired of it. He always loved seeing Nagisa's smile, all innocent and  _shy_ , even a moment before he struck with his knife or the clap. Nagisa was a master at hiding his true emotions, but Karma was getting better at reading Nagisa's moods—enough that he knew now when to back off unless he wanted to get a knife pressed at his throat, and not at all in erotic manner.

That was the reason why the red-head stopped at the doorway into their living room, eyes glued carefully at the back of Nagisa's head. The other seemingly hadn't noticed Karma's arrival for he hadn't turned around to acknowledge Karma at all, but the constant  _click click_ noise that filled the room raised warning signs inside of Karma's head. He was familiar with that sound—of Nagisa flipping his switchblade idly open-and-close again—which usually would be a sure sign of Nagisa's irritation.

The smile on Karma's face turned wary. He still remembered their particular argument this morning—about Karma not attending their precious 3-E class' reunion due to additional summer classes—and wondered if Nagisa's annoyance had stayed even after meeting their old friends. He wasn't looking forward to another argument, partly because he was tired, but mostly because in the end he would never win against Nagisa, and yet he knew he'd have to confront his lover sooner or later.

Karma bit back a sigh. Knowing there was no use in pending the inevitable, he fixed a grin on his face and stepped forward. His voice was light as he drawled out, "I'm home~"

The sound of flipping blade stopped immediately. Karma didn't let that deter him, moving closer instead until he could lean against the back of the couch and planted soft kiss on the top of Nagisa's head. When he didn't feel any cold steel against his skin, Karma's movement become bolder and he rested his chin on Nagisa's head.

"You're late."

"Mm, there was an extra class on the last minute. How was the reunion?"

"I didn't stay until it's over," Nagisa flipped the switchblade open again. Karma's eyes were immediately drawn onto the steel—and he noticed it was Nagisa's favorite; the one with red handle which was Karma's present for his twentieth birthday. "It didn't feel right without you there."

"Oh," Karma commented shortly although his mind was focusing on all the things Nagisa  _hadn't_  said. The bluenette's voice was calm and collected—so much that it couldn't be anything other than a ruse. He also noted that the switchblade hadn't been closed yet. The smile on Karma's face turned bland. He decided to abandon his position in order to sit beside Nagisa. "I hope you still had fun there though."

"Oh, yes. I had plenty of fun," the smile on Nagisa's face turned more sincere and Karma allowed himself to relax. "Isogai-kun and Kayano-chan said something… interesting."

"Hmm? What's that?"

Karma's question hung between them as Nagisa flipped the switchblade close again. He seemed to contemplate his answer and the redhead wisely waited. It wasn't a good thing to rush Nagisa, because he'd always take things on his own pace nevertheless and, admittedly, usually it would be for the best.

So, Karma waited. He entertained himself by watching the expert movements of Nagisa's fingers as they spun the knife. He had always been fascinated by Nagisa's fingers; those slender, long digits were a lot more skillful than they looked like, especially when they were curled around a knife's hilt. Although, to be perfectly honest with himself, Karma loved to see the knife combined with Nagisa's mouth even more. Now  _that_ was something that would never fail in making Karma's blood ran hot with desire.

Unconsciously Karma swiped his tongue across his dry lips. He could feel his desire rising even from the mere thought and knew, from the quick glance Nagisa gave to him and the way his lovely blue eyes were glinting suspiciously, that his reaction wasn't missed by the apprentice assassin. Not that there was anything wrong with it—Karma had always been very open about his fondness and desire for Nagisa and he had no intention of hiding it at all—which was why he only replied with a lazy smile.

Nagisa rolled his eyes but the smile on his face hadn't disappeared and it made Karma relax further. He was still certain something was bothering Nagisa, but whatever that was, it wouldn't be that serious if Nagisa could still give him that kind of smile. He leaned back against the couch, head turned towards the other as he prompted again, "So? What did Isogai-kun say?"

"Do you know what people usually call us?" Nagisa asked in return instead of answering. There was quick sequences of  _click, click_ as the switchblade opened and then closed again.

"… No?" Karma answered cautiously, wondering whether he should have known about it beforehand. While he had acknowledged his friends from 3-E very much, he also knew most of them was quite mischievous; the probability of them actually giving a disparaging nickname was small but not nonexistent.

The smile on Nagisa's face was a sight to behold. The curve of his lips was all at once indulgent yet exasperated and it should be innocent enough if not for the dark aura around him that actually made Karma shiver. Thankfully it didn't last long. When Nagisa next spoke up, the dark aura had mostly dissipated as the bluenette let his amusement and resignation won over his irritation:

" _Carnage_ , Karma-kun. They call us carnage—as if we would leave piles of dead bodies behind us!"

Karma blinked slowly; his mind needing a moment to comprehend Nagisa's words. When he did, though, his lips curved into a familiar smirk. His amusement only grew when Nagisa gave him an unimpressed look. "Don't look at me like that," chuckling a bit, Karma then stretched and linked his fingers together behind his head. "Though, I think that nickname isn't that bad. It fits us a lot, actually, considering we did graduate from an assassination classroom."

"I know you'll say that," Nagisa sighed again. "but I don't particularly agree with that nickname."

"Hee, why is that?" leaning towards Nagisa, Karma then reached out to take the knife out of the bluenette's hand. Thankfully, Nagisa was willing enough to release it, fingers uncurling like blossoming flowers just from Karma's soft caress. A soft smile was given as a reward before Karma leaned back to his own space and played idly with the knife. He wasn't looking at Nagisa as he continued, "Is it because you think the nickname is too awful for us? Or… is it because it makes your work seem  _sloppy_? After all, only lowlife assassins would leave dead bodies after their trails, right?"

Karma's question seemed to surprise Nagisa, so much that his whole body froze up. But then a smile played on his face; a smile so soft and beautiful it would throw people off-guard. He chuckled a little before turning towards Karma. His smile grew wider when he noticed that Karma, unlike most people, only looked at him cautiously instead. It made warmth immediately blossom in Nagisa's chest.

"Sometimes, I think you know me too well, Karma-kun," said Nagisa. The smile on his face faltered as he ducked, suddenly shy from admitting that. His bashfulness only lasted for a moment though, because then he continued to lean further towards Karma, bracing one of his arms on the couch beside the redhead's face and bringing his lips very closely to Karma's. Their eye-contact hadn't been broken; Nagisa felt his heart beat faster from the sheer intensity and  _want_  he could see inside Karma's eyes, which only made this all the more exhilarating.

"Is that a bad thing?" Karma asked in hushed voice. He could feel his lips brushing against Nagisa's faintly as he spoke. The sensation brought a shudder to Karma's spine—that, and another spike of arousal.

"I wouldn't say that," Nagisa's eyes flicked to Karma's parted lips; his own voice sounded breathless. Then Karma's free hand cupped his cheek, fingers gently tilting his chin up so that their eyes met once again, and Nagisa let his body fall a little until the heat of Karma's body seeped through his shirt from their touching chests. "On the contrary… I think I'm really grateful for that."

Karma chuckled. His huffed breath fell upon Nagisa's face, making the bluenette's eyes flutter close. He then leaned forward, ending their teasing by properly placing his lips upon Nagisa's in a sweet kiss. He kept his eyes open to see Nagisa's expression softened and then the bluenette sighed, opening his lips just a little. Karma was unable to resist the temptation as his tongue darted out to lick the seam of Nagisa's lower lip.

"Mm." It was always dangerous, kissing Karma, because never had Nagisa got drunk so fast on anything except for it. Alcohol he could take quite well—and knew his limit enough to stop when he had to—but kissing Karma … kissing Karma was a whole different experience altogether. Just from the slight brush of their lips, Nagisa's blood would run hot and fast inside his veins, it made him feel bold and reckless, and the worst was that, unlike alcohol, Nagisa didn't know how to stop. He couldn't stop even when he knew he was losing control. Instead, it made him want more—more of the tingly feeling he got when Karma pushed his tongue in and caressed the roof of his mouth; more of the sharp bites that sent electrical jolt to the core of his being whenever Karma bit on his lip.

As their kiss got heavier, Nagisa moved up, swinging his leg around so that he could straddle Karma properly. His hand, the one that had been resting beside Karma's face, curled on the back of Karma's head, fingers entangled with the red strands. His other hand seemed to move on its own, slipping up beneath Karma's shirt, caressing at the abdomen. Nagisa tried to smile in their kiss as he felt muscles jerk under his fingertips. He managed to actually do it when Karma squirmed slightly away.

"Still ticklish there, Karma-kun?"

"Only when you don't do it properly."

They smiled at each other; secretive smile that held so much affection and understanding of one another. Nagisa chuckled, for no reason but the bubbling happiness inside of him, and gave Karma a peck on the lips. It was replied by another smile and Karma gently caressing Nagisa's hair away from his face. The blue strands had been cut. It could no longer be tied into twin tails, but it still went longer than Nagisa's nape and Karma loved it no less.

"Shall we take this to the bedroom?"

"Mm, not yet I think," Nagisa answered and then the smile was back—the one that Karma loved to call his assassination smile. This time, Karma looked even more wary than before and perhaps he should be. Nagisa did have hidden intent, after all.

For Nagisa, knowing that he had instilled some fear in Karma's mind was even more intoxicating than kissing him. Karma, who was known as the genius in their class; who took political studies in order to make his dream as a bureaucrat come true in the future—which it would, Nagisa had no doubt about it—and who could lay an attack when you least suspected it. In the past, there were times Nagisa had felt inferior compared to Karma, but that was before he realized he was the only one who felt like that; Karma had always seen him as an equal.

"Should I be worried here?" Karma asked. He tried to play his anxiety off by smirking smugly even though he knew Nagisa wasn't fooled. They both could clearly feel the way his heartbeat accelerated in his chest, after all.

"You never have to be worried of me," Nagisa almost crooned. He caressed Karma's cheek with one hand in order to distract him while he took his knife back from Karma's hand with the other. Nagisa put his lips right beside Karma's ear as he whispered, "I will never hurt you… any more than you want."

Karma tried to resist a shudder at that and failed completely. He chuckled breathlessly as understanding dawned onto him. Then there was the cold bite of steel first on the side of his cheek. It moved lower to the side of his neck, dangerously close to his artery. Karma gulped although it wasn't really fear that he felt. He rested his head back on the couch, giving Nagisa more access to his (for now) unblemished throat. In response, the knife went even lower, caressing his collarbones teasingly.

"I'm glad I didn't wear my favorite shirt."

"Well, you have always been smart, Karma-kun. So that really isn't surprising."

Karma would have retorted at that, but then Nagisa was pulling away and peering up at him through his fringe. The sight of Nagisa's eyes, so dark with his pupils dilated they ate the whole irises, rendered Karma speechless. There was no killing intent he could detect from Nagisa, but the bloodlust was rolling off of him like waves. It was a different kind of bloodlust with the one he'd usually direct to his targets though—or maybe Karma's sense of danger was just  _that_ twisted after years surrounded by said assassin—because it didn't scare Karma as much as it turned him on.

"I can't take deep wounds this time. I still had extra classes tomorrow."

"Tomorrow is Saturday."

"Yes, but I have to take the class if I wanted to graduate a year faster than my peers."

"Fine," said Nagisa as if it was no problem at all. But the bite of his knife on Karma's skin that actually drew blood belied his nonchalant acting. He had a reason to be mad too, because usually they would spend the whole Saturday together and Nagisa didn't like to be a second priority. He leaned down to lap at the blood pooling on the hollow of Karma's collarbones, delighting in the way the man above him hissed from the sting. "You'll just have to pay me back for it."

"Yes." Karma agreed without hesitation. Although, whether it referred to Nagisa's words or the way Nagisa continued lapping the blood off of him while moving the knife even lower, tearing through Karma's shirt as easily as if it was butter, was unclear. He was in no condition to elaborate either, because the pain-pleasure Nagisa inflicted on him was messing with his train of thoughts. Not that he would complain about it.

It was a fact both of them knew really well. Nagisa even had the gall to grin cheekily at him. Any other day, Karma would've struck back with words only because he didn't like to lose, but every time they did this—every time Nagisa put his knife onto Karma's skin—he was turned into a mindless person caring only for his pleasure. The pain was only the fuel Karma needed to get to his climax, because nothing without challenge would ever be interesting enough for him.

"Relax, Karma-kun, let me take care of you," whispered Nagisa sweetly as he kissed Karma's lips. He pulled away once again when Karma tried to deepen it, resulting in a frustrated groan from the redhead which Nagisa ignored. He waited until Karma's tense muscles loosened up beneath him before continuing his movement; the knife slowly slicing away at Karma's shirt here and there until it was nothing more than battered rags, occasionally leaving red trails behind.

Carelessly Nagisa let the shirt—or what was left of it—drop around them. The knife rested then atop Karma's bare chest, but it wasn't poised to harm for only the flat surface touched Karma's skin. This was something Nagisa would always done. Once he had managed to get rid of Karma's clothes, he'd take some time to admire his partner's body. Karma might not aim to be an assassin, but he wouldn't let his body go soft—and it showed on the firm muscles on his chest and stomach.

"I've always been jealous of your body," Nagisa confessed for the umpteenth time. He caressed Karma's chest with his free hand, thumb brushing against one pebbled nipple and making Karma released a shuddering breath. He smiled. "I'll never get such strong body like this. You may even overpower me if one day we ever fight each other."

"That is a day that will never come," responded Karma huffily. He grabbed Nagisa's free hand, bringing it towards his lips to nip at the fingers. His dark eyes showed his impatience clearly as they gazed at Nagisa's. "You're talking too much, Nagisa-kun. Should I take over from here?"

The response Karma got at that was a sweet laugh. Then Nagisa gave him a kiss as apology. "Sorry, I won't do that again," promised the bluenette.

"You'd better not. I don't think both of us could stand prolonged torture by now," said Karma as he released Nagisa's hand. "Now, do continue."

"People don't usually give orders when they're held on knife point, Karma-kun," Nagisa shook his head in amusement because he knew the statement would only be twisted into a praise in Karma's mind. He moved before Karma could give any smart reply, placing the point of his knife just beneath Karma's collarbone. That certainly made the redhead shut up as his whole body shivered from the feeling of cold steel against his hot skin.

The knife moved lower until it reached the sternum, circling Karma's nipple teasingly but not yet drawing blood. Once or twice it nicked at the hardened flesh, eliciting a groan from Karma, but Nagisa was careful enough to not break skin. He enjoyed the way Karma's body tensed up beneath him, even if it meant he had to adjust his seat because Karma was certainly getting harder down there.

"Stop teasing me." Karma growled. His hands, which were still laying limply around him, twitched with the desire to pull Nagisa close, but he knew it would only ruin the mood, so Karma decided to grip at the couch tightly instead. Touching Nagisa was off-limit right now; he would need other options to keep him anchored.

"Is that how you should talk to me? Very rude," Nagisa clicked his tongue. The knife was drawn on a long, horizontal line below Karma's nipple with enough force to make him bleed. Nagisa leaned down to once again lick at the blood and murmured against the skin, " _Beg_ , Karma-kun. I want to see you ditch your pride here."

Karma gnashed his teeth. If there was one thing he hated more than losing, it was begging. His pride would never allow him to beg anyone for anything. He had always been self-sufficient, capable of getting everything he wished for by himself—there was never any need for him to beg. He knew this was also a part of their power play—Nagisa assuring his own dominance over Karma by making him crumble for once—but still he tried to fight it.

At least he did until Nagisa moved lower, drawing the knife down Karma's hip—where he knew there was a N literally carved into the skin-and to his inner thighs with pressure hard enough to be felt despite the jeans Karma wore. The jerk of Karma's hip was involuntary. Then the knife—the  _bloody_  knife—brushed against his groin and Karma's resolve crumbled into ashes.

"FUCK! Please, just get on with it, Nagisa!  _Please_!" His voice broke at the end, but Karma couldn't care about it anymore.

In answer, Nagisa kissed him hard before he threw the knife away. Immediately, his hands worked on Karma's belt and zipper, until finally he could pull the jeans and the red boxers underneath down. Nagisa didn't bother taking it fully off, letting it hang around Karma's ankles instead, before he moved away in order to grab the condom and lubricant they always kept beneath the couch.

He took his own clothes off completely before walking back towards Karma. Nagisa noticed that the redhead's attention was glued to his erection. It made him blush fetchingly, although he didn't bother hiding from the gaze that seemed to eat him whole. Nagisa refused to meet Karma's eyes as he rolled the condom onto the other's erection. He only looked up once he had smeared generous amount of lubricant onto the hard flesh.

Karma smiled, gently for once, as he saw Nagisa biting his lip in hesitation. He cupped Nagisa's cheeks with both hands, gently pulling his forward until their lips met in yet another kiss. Nagisa sighed softly onto the kiss as he adjusted his position on Karma's lap. Both of them moaned when Karma's erection rubbed against Nagisa's opening.

"I need to prepare you," Karma panted between their kiss. His hands, now free to move, went lower until they could grab at Nagisa's ass cheeks, spreading them while fingers searched for the pink opening and dipped inside lightly.

"Ngh, n-no," Nagisa moaned, but he couldn't stop himself from pushing down onto Karma's fingers. Two of them were inside of him now and the intrusion made him feel full yet unsatisfied at the same time. He nipped at Karma's jaw before pushing him away with enough force that Karma's hands retreated from their position. He shook his head to answer Karma's questioning look. "No, I'm fine. I don't need preparation."

"But that's—"

"Karma-kun," Nagisa cut in. The look he gave to Karma was enough to make him fall silent. "I want you.  _Now_."

There was nothing Karma could say to that. He could only stare, speechless, until finally he smirked as always. His hands moved towards Nagisa's slim waist, holding the other loosely as he buried his head on the conjunction between Nagisa's neck and shoulder. He inhaled deeply, getting familiar with Nagisa's musky scent once again. "Don't blame me if you're sore tomorrow." He murmured before licking Nagisa's neck, for once loving the sharp taste of salt on his tongue, and peppering soft bites onto the white canvas.

Nagisa laughed breathlessly. "I know you'll take care of me nevertheless."

"True," Karma admitted with a smile. He lifted his head up in order to look at Nagisa's eyes tenderly. "Alright. We'll do this your way then."

"Thank you." Nagisa kissed the tip of Karma's nose and then he was reaching back, grabbing at Karma's cock and positioning it against his own opening. His eyelashes fluttered against his cheeks as he slowly lowered himself down, until finally he was sitting on Karma's lap fully with a throbbing flesh inside of him. Both of them moaned at the sensation. Nagisa rested his head on Karma's shoulder as he took few shaky breaths to calm himself.

Meanwhile, Karma was tracing comforting circles on Nagisa's waist and back. He too had his eyes closed. They spend a few minutes staying like that, enjoying the feeling of being completely connected, of finally coming home in each other's embrace. Then Nagisa lifted his head and started to move—and all Karma could do was holding him tight as pleasure washed upon him.

He was already at the edge from all the foreplay they did, so Karma knew he wouldn't last long. Thankfully, judging from the pace Nagisa had set—which was too fast, too frantic—neither would the bluenette. Determined to get them both off at the same time, Karma's hand sneaked towards Nagisa's cock, grabbing it and pumping to the best he could. A loud moan escaped from Nagisa's red lips as his body trashed even more violently in Karma's lap.

"K-Karma-kun," Nagisa gasped. His thighs was starting to hurt from his movements, but the burn felt sweet and, coupled with the way Karma fisted his cock, the pain turned into pleasure which overwhelmed him. A sound between sob and moan slipped from him as his climax was getting closer and he reached out with one hand to harshly yank Karma down.

Their kiss this time was rough and sloppy, broken only with their groans and pants, until finally Nagisa shifted a bit and Karma's cock nudged directly against the nerve bundles inside of him. Nagisa's mouth fell open in a silent scream as he came, spilling his seed all over their bodies. He slumped forward afterwards, boneless and unable to do anything much except nuzzling at Karma's chest which was moving up-and-down rapidly beneath him.

Karma followed him soon after, his own climax reached as Nagisa's body contracted in his climax, gripping Karma's cock impossibly tight. He bit his lip until the taste of copper filled his mouth in order to hold back his scream as he finally came. Then, not unlike Nagisa, all that Karma could do was slumping back onto the couch while embracing his precious treasure tight and whispering soft words of adoration.

Nagisa smiled, basking in their afterglow and the obvious affection Karma showered at him. They never said 'I love you' because it wasn't necessary. Nagisa didn't need empty words when Karma's feeling for him had always been shown in his every action. So he kept the silence between them unbroken as their heartbeats slowly returned to normal and thought, not for the first time, that perhaps he loved this moment more than the sex.

(Not that Nagisa would ever refuse more intercourse with Karma because, frankly, the power he gained in those moments were addicting.)

Once he had recovered enough, Karma gently deposited Nagisa to the empty seat beside him. He smiled fondly when Nagisa only mumbled something in response, clearly tired out and drowsy, even as Karma moved out of the couch. The condom was dispatched swiftly, Karma taking few tissues with him as he walked back towards Nagisa to clean them up. He pulled Nagisa back onto his lap when there was no more cum on their body and simply held him with Nagisa's head tucked beneath his chin.

"Well," Karma broke the silence. There was an obvious smirk in his tone as he continued, "I wouldn't refuse another round of that."

Nagisa just had to laugh, because although sometimes he felt Karma was too careless about flaunting their relationship, he couldn't exactly disagree with his statement. In the end he decided to make himself more comfortable atop his human-pillow. "Mm, yes. I wouldn't refuse it too."

"Nagisa-kun," Karma called before Nagisa could truly fall asleep.

"Mm?"

"Do you still mind the nick people gave for us? Carnage?"

"… No," Nagisa gave Karma a sleepy smile. "I think it does fit us after all."

.

.

.

— **End.**


End file.
